Tulip Bulb Bloom Time Calculator

If tulips won’t flower, they disappoint us in particular ways: We planted them in fall all hopeful that come March there’d be color, but instead there are just sad stems, or maybe no stems at all, and just some green leaves. If tulips don’t flower, it’s frustrating because we expect them to!

The good news is that it’s rarely our lack of gardening skill. Most often, its simply not understanding the concept of chill hours, which is where calculator comes into play. Once you tell it what variety of tulip (and your zone), it do the math for you. Turns out that a certain length of cool weather trigger their bloom.

Why Your Tulips Are Not Blooming

Bulbs get planted deep, why? The first reason is to prevent critters from eating them. Reason two: because deeper planting provide a cooler environment for bulb’s emerging roots, which are vulnerable to disruption by freeze/thaw cycles if they’re exposed higher up. In fact, the classic “rule” for planting depth is to bury bulbs twice as deep (or 2-3 times) than their own height. This keeps their roots in a relatively constant temperature zone and ensures that shoot has some stored-up energy once spring arrives to warm things up on top. Fine-tune that a bit based off whether you have sandy soil or clay (clay will be heavier then sand), but sticking roughly to that depth-to-height relationship will help you get uniform bloom in bed.

The second critical variable in bulb gardening is choosing the correct variety for your climate zone. For instance, Triumph tulips and Darwin hybrids is gorgeous. However, they require strict attention to a regimen of at least fourteen weeks of chill (below forty-five degrees). In warmer zones where the night-time temperatures don’t regularly dip down that low over time, those bulbs won’t be happy trying to flower here.

The species tulips and the Kaufmanniana sorts is more forgiving. They evolved in harsh conditions and require less total chill. They also tend to spread better then the exhibition hybrid kinds. This is another difference worth knowing as it spares you heartbreak (and dollars) before you buy any bulb.

TULIPS forced indoors need careful attention to timing: They have to be planted with patience, not just tossed into a container and expected to come alive by December. That’s because they develop their roots in cool, dark conditions while the shoots remain dormant; you want them to move right into the warm, bright world when white roots poke out of bottom of container (but not before or after), or else you’ll end up with nothing but a bunch of leaves and no buds. Use this handy chart as a starting point to figure out backward exactly when to plant for desired bloom day.

DO I chill my bulbs myself (and what about those of you who live in warm climates)? If you have a refrigerator that’s never used for food, you can chill them at home. For instance, fruit such as bananas and apples give off ethylene gas that damages the tulips’ flowers. Simply wrap the bulbs in damp moss (no touching!) in a plastic bag. To be safe, buy prechilled bulbs (it will cost more) from a reputable nursery; this is the option if your kitchen fridge holds leftovers. In an uncertain year, peace of mind should of come at a price.

Tulips are a great plant for growing (and then again), they’re not, unless you guide how they grow almost as much as you do the conditions of their growing place. Because each tulip is a biologic clock ticking away since it left the field in high summer, when it was cut from the ground and dried. If you time yourself to its inner clock, tulips reward you with vivid and firm flowers that seem to belong where they stand. The trick is getting the chill part right… And therefore the spring part too.

Follow these steps: